Casting device for dental purposes.



i To oZZ whom it may concern:

. N UNITED STATES PATENT. OFFICE', a

ALEXANDEQ orv "SEATTLE,

CASTING DEVlCE :FOR- DENTAL PURPOSES.

`Specification of Letters Patent. Paten-ted Sept. 10, 1912.` l

Application led March 3, 1908.-, Serial No. 413,043.- f

Be it known that we, JOSEPH FRANCIS ALEXANDER and WILLIAM GRAHAM' ALEXAN- DER, citizens of the United States, residing at Seattle, in the county of King and State of VVaShingtOn, have invented a new and useful Casting Device for Dental Purposes,

of which the following is a clear and concise specifica-tion. y

Our invention relates to castingdevices in which a paraffin or wax pattern is sur- 4 rounded bya porous cement investment contained within a suitable casting flask and is advantageously used for dental purposes. 7e do not wish to be limited to this use however, as we may desire to employ our invention for other casting purposes.

The objects of'our invention are, to provide a suitable flask for casting purposes with a means forv applying a partial vacuum to draw the metalinto said flask; to provide a porous, fusible or combustible partition i between the investment and thel air pump connection. as minor objects bythe construction now We accomplish these as well preferred byA us'and illustrated in the accomf panying'drawings in which' Figure l is a perspeetiveview of our device; Fig. 2 is a section through the center .of the fiask; Figs. 3, 4 and 5 are detailed views of the investment supporting' means; Fig. G is a section through the center of the hood of our device; Fig. 7 is a perspective view of the capto the hood of our device.

Similar reference numeral-s refer to similar parts throughout the several views of our device as illustrated in the accompanying drawings,

, We have provided a fiask 1 having a suitable investment of investment compound,4

. remove the pattern therethrough by heating the flask l and cement 2 contained therein.

The metal which may bedepositcd in the recess 5 provided at thc end of said gate 4 is then reduced to a molten condition; and

to insure the mold 3 being filled with metal we have provided a suitable connection 6 communicating` with any for'in of air pump 7 thus inducing the metal to be drawn t0- device.

ward said connection 6 when a'fpartial vacuum is obtained in said air pump ,7.

IuFig. lv we have illustrated our. device in its complete form with the flask stationary and provided with a heating means, the air pump 7 being secured to the panel 31 by meansof the straps 32 adapted to clamp said air pump 7 to said panel. We have provided a bracket 33 adapted to support a hood 34 and a cap 35 to said hood in coaction with the pipe 36 connected to said air pump 7 by meansof the T 37 and nipple 38. Said T 37 is also provided with a'icock 39 adapted to relieve the partial vacuum in the pipes .and in the pump cylinder of `our The hood 34 and cap 35 are of the general shape of an inverted cup. The lower portion ofthe cup or hoodl portion 34 is disposed substantially annularly around'the fiask of our device and when the cap ofv said hood is in place the heat of the burner is maintained constantaround said flask thus means a thermal efficiency of the burner isl increased. The flask' is supported bythe pipe 36 which is secured to the airpump.

of our devi-ce, thus it will be seen as above stated that as the lower edge of the hood 34 rests on the bracket 33, said bracket providing a support at substantially two bearing points, that the pipe 36 forms the third support. The flask l wehave shown as being rigidly connected to said pipe 36 and permanently held over a Bunsen burner-40 which is provided with an air regulator 41 and hose 42 adapted to supplygas thereto. Said fiask 1 by this constructionA is necessarily provided with a eoinbustible or porous disk 43 which supports the cement or `invest-in ent 2 which is deposited there in said flask in a liquid state until set. When t-he heat is applied to said fiasksaid combustible disk 43 willbe burned and will permit the suction on the pump to act upon the mold 3 thereby aiding the flow of metal in the mold and insuring a perfect casting. We do not wish to be limited to a combustible disk 43, however, and have shown a disk composed of porous cement 44 reinforced by a wire screen 45. The disk 43 when iuade of porous material serves substantially the same purpose as the combustible disk, ex-

cept that a disk made of combustible material has to be renewed each time a heat is taken off. The porous cement with a Wire reinforcement being substantially fire proof is slightly more expensive from the point of manufacture but is preferred by some operators.' To maintam a partial vacuum on our device without holdino' drawings.

Ilaving thus described our invention what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a dental casting device, an air pump and a flask rigidly connected theretoand a detachable supporting means provided at vthe base of said flask preventing investment compound in said flask from entering said air pump connection and adapted to permit the circulation of air into said air pump connection.

2. In a dental casting device, aflask supporting investment material, an air pump connected at the base of said ask and a removable investment supporting -means whereby said investment is held in said flask andprevented from gravitating into the air pum connection when in a plastic state.

3. n a dental casting device, a ask and a mold of porous investment vmaterlal supported in said Hask, an air pump connected to the base of said flask and means preventing said investment when in a plastic condition from gravitating into the connection to said air pump.

4;. -In a casting-device, a flask, a heating means thereunder, an air pump connected to 'said flask, means whereby investment material is prevented from gravitatng into Said connection and whereby said flask may be fixed to said connection during the process of filling said lflask with said investment material and during the process of cast-ing.

15. In a cast-ing device, a flask, an air pump connection at the base of said flask, a heating means and an investment supporting device adapted to support said investment ma- 6. In a casting device, an air pump, a flask secured thereto, whereby said pump and flask are connected during the process of melting and casting and a removable supporting member provided between said flask i and said pump.

7 In a .casting device, a mold support provided with a removable perforated base, a porous mold mounted thereon, an air chaluber formed on said base adjacent said perforations, means connected with said chamber for maintaining a vacuum,'-and means for suddenly reducing said vacuum, the influx of air into said vacuum maintaining means forcing the metal into said mold.

8. In a casting device, a flask and an air pump connected thereto, a hood and cap, and means for removably supporting said hood in fixed relation with said flask whereby said ask may be filled when connected to said pump, and means for supporting the investment'material in said flask when in a plastic state whereby said investment material is prevented from gravitating into said connection.

9. In a casting device, a flask and an'air pump connected thereto, a hood and cap', and means for removably supporting said hood in fixed relation with said flask whereby said flask may be filled when connected to said pump. means for supporting the investment material in said flask when in a plastic state whereby said investment material 1s prevented from gravita-ting into said connection, a heating means for said flask whereby metal may be melted, said air pump being connected to said flask while said metal, is being melted forcing said metal into said flask by the air passing through said investment material and the support therefor when said JOSEPH FRANCIS LEXANDER. WILLIAM GRAHAM ALEXANDER.

Witnesses:

PAUL A. TALBOT, R. H. Hum). 

